1. Field of the Invention
The present invention generally relates to the field of integrated circuits. In particular, the present invention is directed to an integrated circuit macro placing system and method.
2. Background of the Invention
The layout of many types of integrated circuit chips involves locating a plurality of pre-designed integrated circuit functional blocks, i.e., macros, aboard the chips. For example, for chips such as general microprocessor chips, macros are typically placed during the floor-planning phase of design, i.e., the phase in which the overall layout of the chip is performed. In this context, macros are generally arranged on the chips in spaced relationship with one another, with the wiring connecting the various macros to one another being essentially customized to the particular arrangement of macros resulting from the floor-planning phase.
At the opposite end of the floor-planning spectrum, many macros utilized in application-specific integrated circuits (ASICs) are often designed to be placed immediately adjacent one another so that immediately adjacent pairs of macros can share common wiring that connects the macros to the appropriate electrical networks, e.g., a power network (such as VDD), a ground network (GND) or a signal network, located on the various metal levels of the chip. In ASICs, the electrical networks are typically in the form of regular wiring grids that extend over the entire region(s) in which macros may be placed. Consequently, in the floor-planning phase of ASICs, many of the macros are simply placed side-by-side without the need to design custom power ground and signal wiring.
Between the two extremes just mentioned lies an intermediate design approach in which macros are not necessarily uniformly designed so as to be placed immediately adjacent any other macro as is typically done in ASIC design, but are also not necessarily incompatible with one another so as to require custom wiring. In this intermediate design approach, some macros may be configured so as to allow placement immediately adjacent one another so that they may share some common wiring to the electrical networks. However, there is presently not an efficient and effective way to determine if macros are compatible with one another so as to take advantage of ability to place them immediately adjacent each other and share common wiring.